Cement, concrete, and plaster



Patented Dec. 14, 1926.

UNITED STATES more??? PATENT OFFICE.

VICTOR LEFEBURE, OF LONDON, ENGLAND.

No Drawing. Application filed February 29, 1924, Serial No. 695,966, and in Great Britain March 5. 1923.

-ter, or other liquid onby theaction of the water contained inthe. latexcoagulum. Hot or cold vulcanizing agents may added, the vulcanization of the rubber contained in the-mass being thereby efiected with or without the application of heat as may be necessary.

Th invention can be put into practice in a number of different ways. According to one way rubber lat is taken and, suitably coagulated, and then mixed with for example mud ce'm ent, which sets by absorbing water from the rubber latex.

By another method rubber latex, is mixed with a paste of the liquid setti iig cement and water say Portland cement and water, or

w and water, the latex be made into a paste with a er egg e a filler \siibstantially inert o rubber arr o. ie fvulcanized or unvulcanized rubber concrete.

liquid setting cement and thesaid paste...

added to dry Portland cement powder, or gypsum, or to Portland cement or gypsum and water paste. The products made by these processes are hereinafter called unvulcanized rubber concretes. I, v I have found that the mode of separation of the rubber from the latex, and the physical form in which the rubber is separated are important. In general, the actual rubber should be thrown out-in a state as finely divided as possible. This can be done by employing small percentages of a suit able coagulant such as alum, as is wellknown in connection with latex and/or by precipitating the latex upon one of the fillers such as finely divided silica before or during the gauging of the Portland cement or plaster of Paris. The chemical nature of the cement or plaster will usually determine what method should be employed. For instance, with Portland cement, alum is used but with plaster of Paris I prefer to precipitate the rubber on an inert filler without the addition of a special precipitant.

A second form of product hereinafter called vulcanized rubber concrete, can alse be made. One suitable process for manufacturing such a product is carried out by mixing either with the cement or the latex, or with both, sulphur and an accelerator, or other vulcanizing agents. The mixture is then given a suitable heat treatment, either at a high or at a low temperature according to the vulcanizing agent and the method of vulcanization used.

Heat may be applied to the mass during or after the setting period to effect vulcanialstf'bTe' zation, but in the case of Portland cement the most suitable period seems to be between the initial and final sets. Heating by direct steam is a suitable method.

The products made by processes according to this invention can be applied to the manufacture of a composite product in whichvulcanized rubber concrete, or unvulcanized rubber concrete, is laid in a layer on ordinary cement or cement concrete, or in which vulcanized or unvulcanized rubber is laid in a layer on vulcanized or unvulcanized rubber concrete. The layers adhere, and a layer of vulcanized or unvulcanized rubber can thus be aflixed to a foundation of cement or concrete by means of an intervening layer of g In many cases the addition of rubber aveakens the final product as regards mechanical strength, but this can be overcome when necessary by the use of compression as in ordinary cement practice.

Both the unvulcanized and vulcanized rubber concretes possess the marked advantage of improving the texture and surface of the material, increasing its waterproof propelrties and enabling it to polish more read 1 y.

The following specific instructions for practicing the preferred mode of the invention may be useful parts by Weight of Portland cement are armed with water to consis encv of a /20 parts of water are 1 thick paste; from ,suitable for this purpose. Sufiicient rubber latex is then taken to contain two parts 5?? weight of rubber content. To this rubber latex is added sufiicient of a dilute solution of alum with stirring, to finely coagulate the though woul say that in a typical case I phur (an cement and stirred to a thinnerpaste, which,

is allowed to set.

To make my meaning clearer, I wouldsay that theresultant rubber concrete thus contains the following parts by weight :Portl'apgi gem 100; rubbgg, 2: alum. one-filth.

Where the rubber concrete is required for the'subsequent manufacture of the vulcanized rubber concrete, the. accelerator and suld an tl g fier) are intimately mixed ancement prior to gau ing'with water, suitable quantities of sulpmr and accelerator for the example above being: ''sulphur, 1/l0th of, a part by "thiuram di u w'drked by an weight; accelerator, 1 th ,part by weight.

A" suitable' accelerator is 'tetrametl e, terna 1V8 y f lave ing, the rubber andthe sulphur to the latex 'at'the same, time as the alum is added. In proceeding to a vulcanized' rubber concrete'the mass is allowedto take its initial set in a -mould or former to give it the required shape, and is then taken out ofthe mould or former,usually allowed tothoroughly setand is then; vulcanized,

' preferablyin a steam heated chamber.

: What I claim and desireto secure by Letters Patent is:

'1. A process for producing, a mass, of

hardened'fcementitious material which comprisesm *mixinq together a liquid-settingcement and' finely coagulated' rubber latex,

thoroughly incorporating thesaid materials to produce a pasty mass, and-giving-thepastymass soproduced the required form.

2. A process for producing a mass of" hardened cementitious materiatwhich comprisesinmixing together a llquid-settmg ce- "ment, the liquid necessary forthe setting thereof, and finely coagulatedrubber latex, thoroughly, incorporating the said materials to produce a pasty massyand' giving the pasty mass so produced the required form.

' 3. A. process for producing a mass ofhardened cementitious material which comprisesin mixing together a, liquid setting "cement, finely coagulated ,rubberlatex, and

a vulcanizing agent, thoroughly incorporat ing the said materials to produce. a pastyw mass, giving the pasty mass so p roduced the required form, and treating the said mass tovulcanize the rubber-therein.

4. A process-for producing a mass- 0f hardened-cementitious material which comprises in mixing together a liquid-setting cement,- finelycoagulated latex, I and a hot vulcanizing agent, thoroughly incorporating A the saidmaterials to produce a pasty mass,

giving the said pasty mass the required "form,

and treating the said mass to effect the vulcanizationof the rubber-therein by the application of heat after the initial setting of the cement in the said mass has taken place.

5. A, process for; producing a mass of hardened cementitious material which comprises in mixing together Portland cement, finely coagulated rubber latex, and a hot vuicanizing agent, thoroughly incorporating the said materials to produce a pasty mass, giying the said pasty mass the required form, and treating the said mass to effect .the vulcanization of the rubber therein by the application of heat after the initial setting of the. cement in the said mass has taken place.

6., A process for producing a mass of hardened cementitious' material which comprises in mixing together Portland cement, finely coagulated rubber latex, and a hot vulcanizing agent, thoroughly incorporating the said materials to produce a pasty mass, giving the pasty mass so produced the required form, and heating the said mass with direct steam between the initial and final setting of the cementto vulcanize the rubber therein.

7. A process for producing a mass of hardened cementitious material which comprises in mixing together Portland-cement, a filler, finely coagulated'rubber-latex, and a hotvulcanizing agent; thoroughly incorporating the said materials toproduce a pasty mass, giving the past-y mass so produced the required form, and heating the-said mass with directs/team between the initial and final setting oftlie cement toyulcanize-the-rubber therein. 7

- 8; A mass ofcementitious material-comprising a layer which contains cementwhich has taken up liquid-and set, and rubber finely and uniformly disseminated through the mass of'the said cement. v I 7 9. A mass of oementitious material comprising alayer which-contains cement which has takenup water and set and rubber finely and uniformly disseminated through the mass of'the said cement. t 1

10. A mass of cementitious material'comprising a layer which contains Port-land cement which has taken up water and set-,and vulcanized rubber finely and I uniformly dissemmated through-the mass -o'f'the saidicement.--

. -11r-A mass of cementttmusmatemal containing Portland cement which has-taken up waterand'set, and wilcanized rubber finely and uniformly disseminated 1 through the interstices thereoft-the said mass beingwa-dherent to a mass of ma'terial containing Portland cementwhich has taken up water and'set and unvul'canized rubber finely dis- --seminated through the interstices-thereof.

l2. A composition of matter-which compr ses aliquid-settmg cement and rubber, in intimate uniform admixture therewith.-

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w e a i a l W M and set and vulcanized rubber finely and uniformly disseminated throughout the mass thereof, surrounding the particles of a subdivided filling material to form a concrete.

17. A composition of matter which contains principally a hydraulic cement and contains also combined Water and finely and uniformly distributed rubber, which is hard, strong, waterproof, and capable of taking a polish.

In testimony whereof I have signed my name to this specification.

VICTOR LEFEBURE.

1A. Q3% /5 Q law/i5 

